1. Technical Field
The present disclosure relates generally to a power supply system and a method of controlling current thereof, and more particularly to a power supply system for driving light-emitting diodes and a method of controlling current thereof.
2. Description of Related Art
Safety certifications provide clear statements and guidance for manufacturing equipment and parts of products, thus providing safe and high quality products to users or operators. The main purpose is to prevent and reduce danger of electric shock, energy hazards, fire, mechanical and heat hazards, radiation hazards, chemical hazards, and so on to ensure life and property safety of users or operators. Accordingly, the manufacturing equipment and the parts of products must pass related safety certifications in different countries before shipping.
At present, most of the power supply manufacturers adopt the following safety certifications, such as International Electrotechnical Commission (IEC), Verband Deutscher Elektrotechnikere (VDE), Underwriter Laboratory (UL), Technisher Uberwachungs Verein (TUV), SLG-CPC Testlaboratory Co., Ltd, or Canadian Standards Association (CSA). In particular, the required applications for safety certifications are more when test projects of safety certifications are more diverse and stringent. For this reason, the required costs of safety certifications are relatively higher, especially the international certification costs. In addition, the internal components and output parameters of the tested power supply must be fixed when the power supply is certificated according to demands of the safety certification. In addition, different models of the power supply need to apply different safety certifications once the output current of the power supply is changed but electronic components and circuit structures are not, thus significantly increasing the research and development costs and manufacturing costs. Therefore, visibility of products and competitiveness of companies will be affected.
Accordingly, it is desirable to provide a power supply system for driving light-emitting diodes and a method of controlling current thereof so that different output currents for the identical power supply can be applied to the same power safety certification.